My girls were like this too...they were 12 lbs 8 oz and 12 lbs 4 oz at their 9 month appointment - and they weren't that small at birth, either - 3.11 and 3.1 . In our case, they were good eaters, although hindered by bad reflux, but even after that got under control they only grew about a pound a month no matter what we did.
In my case I think the weight worries were a little extreme becasue I was breastfeeding and so would blame myself for them not gaining faster. I still occasionally did counts of their wet and dirty diapers at like, 11 months old!
Enfacare lipil should have all the fat and everything she needs in it...I'll bet when Nancy was talking about adding fat to babyfood she was talking about say, stirring a little formula into the babyfood. I've heard of that. I know some pediatricians recommend adding stuff like butter and cream to babyfood for older babies, although ours never suggested it.
I'm over most of my weight worries now...they've been healthy and are on target developmentally, and they eat like a couple of truckers, so what else is there to do? The only time I get nervous now is when they are sick. They seem to lose very quickly over minor illnesses.
It sounds like Olivia is doing great and is just going to be long and slender. (which is not always a bad thing once you reach a certain age :)!)
Alex, mama to:
Parker - born 4/15/2001
Vivian & Lily - born 7/14/2003 at 32 weeks